With the advent of many different sizes, shapes and configurations of containers, it is well-known in the art to die-cut, strip and blank box blanks using an automatic sequential press or die cutting machine. By automating the process and by using computer-aided technology, it is now possible to configure die-cut blanks in a limitless number of dimensions and specifications and, as well, to lay-out any number of blanks on a single sheet of material while automatically cutting, stripping and blanking the sheets with little or no human operator intervention. One typical system and press known in the art is discussed in U.S. Pat. No. 5,337,639, issued Aug. 16, 1994 and assigned to Die-X Tooling Systems.
As described in that U.S. Pat. No. 5,337,639, computer technology, combined with attendant laser technology, has enabled box manufacturers to utilize highly-accurate cutting and creasing dies for producing a planar sheet of die-cut blanks, and also to produce male and female blanking dies used automatically to separate the die-cut or stamped forms from the intervening web or waste portion of the sheet. Automatic blanking, in particular, resulted in a tremendous cost savings compared to the identical operation when performed by labourers using manual blanking means.
The known prior art, constituted by the current technology, includes automatic systems or presses that fed large sheets of material for cutting and scoring of blanks, and also, for automatically-stripping the excess material from the stamped sheet, thereby leaving a flexible thin webbing supporting the various rows of stamped carton forms. The known prior art also contemplated the use of a male and female combination blanking die for automatically-separating the planar forms from the flexible web. The male die, effective through the use of a blanking member, pushed each of the cartons which were blanked through the web and through the apertures in the supporting female die. The thin web typically-remained on the face of the female die while the separated blanks were pushed through the blanking holes into a stack below the female blanking die.
For speed and efficiency, the prior art also contemplated the use of a travelling feed bar and grippers to “pull” a sheet through the various stations of the machine on a continuous chain drive or other mechanism, thereby automatically-feeding the sheet from station to station. Similarly, in most applications, the remaining flexible web on the face of the female die after blanking was also pulled away through the use of the travelling bar and grippers into a waste container or other receptacle at the end of the machine.
The general configuration of automatic die cutting machines for the production of such die-cut blanks is well-known. A sheet of blank material was automatically-interposed, or urged by mechanical means, beneath the surface of a cutting die as part of the first stage of the operation. The cutting die comprised a planar die having specially-configured cutting edges which were created through the use of computer and laser technology, to reflect a particular series of die-cut blank lay-outs for cutting. Once a sheet was interposed under the cutting die on a cutting platten, the cutting die was pressed onto the sheet from below, thereby causing the sheet to be “cut” or “scored” by the cutting die thereabove.
While not essential for a thorough understanding of the present invention, a typical system and press known in the art for automatic die cutting and blanking, which is taught in that U.S. Pat. No. 5,337,639, will now be briefly-described.
The press generally-comprised means for feeding a series of blank, planar sheets into the press or system, e.g., by the use of a travelling bar and appended pulling grippers and then to a scoring and/or cutting station. Thereafter, at the scoring or stamping station, a plurality of rows and columns of die-cut forms were stamped or scored on to the sheet. The sheet, which remained in one piece, was next pulled automatically to a stripping station where much of the small pieces of the excess material around the die-cut forms were automatically-removed. What remained was a series of stamped and creased die-cut forms, which were held together by a thin web therebetween. The thin web and attached die-cut blanks were then automatically-pulled into a blanking station, where the die-cut blanks were completely-separated from the web and were then dropped onto a pallet for transfer.
The blanking station specifically-included the use of a male blanking die/female blanking die combination which, when engaged, pressed and separated the box blanks from the web and onto the pallet. The remaining thin web lay on the face of the female die component and was ready for disposal, in a disposal area at the end of the press. As a result of the blanking operation, a planar blank was produced and was in a condition for assembly, by automatic folding or otherwise, for the insertion of merchandise, food stuffs or other products to be contained therein.
That male blanking die/female blanking die combination included a female blanking die portion and a complementary male blanking die, for blanking or separating die-cut carton blanks or other forms into a detached web and a substantially-planar and unassembled die-cut blank. The die-cut sheet was automatically pulled through the press and over the female die portion, through the use of a travelling bar which had appended gripper fingers which were adapted to grip the leading edge of the die-cut sheet.
After blanking, the web remained on the face of the female die portion and included a series of intermediate web portions which, together, formed an extremely-flexible and “flimsy” “skeleton”, which had to be removed from the female blanking die face. In actual operation, the travelling bar and appended grippers pulled the flexible web over the female blanking die face, including the leading edges of the female blanking die.
In the operation of the blanking dies, the male blanking die was pressed downward through the corresponding through holes in the female blanking die, thereby separating and pushing the blanked carton through the through holes, resulting in die-cut blanks and leaving a web on the surface of the female blanking die. At this point, it was then necessary automatically to remove the remaining web portion from the face of the female blanking die, by use of the travelling bar and grippers.
After the initial cutting process, the entire cut sheet or scored sheet was automatically pulled or urged into a second (or “stripping”) station, for the operation for the stripping-away of most of the excess material from around the cut box blanks. The stripping operation comprised the use of a female stripping tool onto which the cut sheet was automatically-interposed. The female stripping tool had a series of configured openings which corresponded to the cut portions of the cut sheet, and was adapted to receive the male stripping tool from above. The male stripping tool cooperated with the female stripping tool and effectively broke-away and separated the majority of excess material from the box blanks, by being urged downwardly onto the sheet which was arranged over the female stripping tool. It was, of course, critical that the male and female stripping tools be aligned precisely and that the cut sheet be arranged in alignment therebetween, to insure that stripping was effectively-accomplished, i.e., without tearing of the box flank, jamming of the machine or damage thereto. Further, precise alignment was required due to the narrow tolerances which were necessary to assemble the box or container, which was formed from the cut sheet.
On machines so-configured, the stripped sheet was next urged in between yet another series of male and female blanking tools, which were arranged one above the other and which were also required to be in precise alignment. The female blanking tool was adapted to receive thereabove the die-cut blank, which was stripped at the previous station and which had a series of openings directly-corresponding to the shapes of the cut boxes to be blanked. In turn, the corresponding male blanking tool of similar contour to that of the female tool, was adapted to push the cut box blanks free from any remaining extraneous material and through the female blanking tool into a stack therebelow. Accordingly, it was once again required that the male and female blanking tools be carefully aligned and that the sheet to be blanked be precisely arranged therebetween, to avoid problems similar to those described in the stripping portion of the operation. After blanking was completed, the remaining extraneous material was then urged-off the face of the female blanking tool, into a refuse area and the process continues from the beginning.
It was well-known and was recognized in the prior art, that the set-up of the blank cutting machine was critical to efficient and proper automatic cutting, stripping, and blanking of multiple box blanks. The alignment method currently-practised in the art was a manual one, i.e., one which relied upon the senses and the vision of the operator manually to adjust the stripping and blanking tools, through use of the applicable alignment means of a particular machine press. Accordingly, it was not unusual for machine set-up to take anywhere from four to six hours, especially for complex box layouts comprising various series of boxes and orientations. Due to the precision required and to the high tolerances of the components, the method of manually-setting-up the machine required that the machine be “down” for extended periods of time between production runs. This, of course, resulted in diminished-capacity and in diminished-productivity, and thus, affected the overall cost of the production and the price of the box blanks.
Applicant's co-pending Canadian Patent Application Serial No. 2,259,785, filed Jan. 19, 1999, the contents of which are incorporated herein, provided an improvement in a female blanking die for a die cutting machine for die cutting and/or blanking a carton blank, as well as a combination male blanking die/female blanking die, and methods of producing them and elements constituting essential integers thereof are provided herein. The male blanking die/female blanking die combination included a male stripping die which included a template having a particularly-specified perimeter, the template including a plurality of foam plastic pads which were removably-secured to the undersurface of the template. The template was accurately-secured at a predetermined position to the underface of a movable upper plate of the blanking station of the die cutting machine. The male blanking die/female blanking die combination also included a female blanking die including a rectangular framework and a plurality of grid support members, each grid support member having a slot across its upper face, the grid support members being selectively-disposed along the internal perimeter of the rectangular framework. A grid was provided including a plurality of intersecting rails, the pattern of the intersecting rails having a predefined shape. The grid was disposed within the slots atop the grid support members. A plurality of jogger member members were provided which were selectively-disposed along the internal perimeter of the rectangular framework, each jogger member having a particularly-recited structure. The plurality of jogger member members were oriented along the internal perimeter of the rectangular framework in a particularly-recited way. The female blanking die was accurately-secured at a predetermined position atop a lower fixed plate of the blanking station of the die cutting machine. The male stripping die and the female blanking die were accurately-aligned to cooperate to press and to separate the carton blanks from a web holding them together, and to force the separated cartons through aligned openings in the female blanking die.